I think it is a question of the type "which are the best apples or bananas".
I have used the sme server for years in server only mode for years, not because I wanted it but because I got a adsl router modem, with firewall, that I can not avoid.
For a period I expermented with 3 different firewalls, the adsl router/firewall, then the first gateway firewall, a smoothwall, the sme server, the chock firewaall, smoothwall number 2 in front of the lan computers. It gave a some kind of a emotional feeling of living in a computer store or a netcafe, with first of all the sound of fans days and nights. I think there were even a lan sme server inside the second smoothwall for a period. So the days of tripple nat, went pritty well untli I realized there might be more silent heaters for my apartment.
My next planned project is to try to do nasty things with my adsl modem router, so it will bypass all firewall functions and work in a bridge mode, delivering the external ip direct into my lan.
Should I need a smoothwall or should it be a sme gate keeper ?
Well the last thing I would think about was that the sme server is not safe enough.
So I think the more right question would be: Should I like to join the user community of the sme server only, or should I like to join the user comunity of smoothwall as well.
Since "the days of tripple nat" I have married, so for many other resons, and for safety reasons, the best choice be only that single sme gateway server.
If I still had a lot of time and interest of how firewalls really work, well then the smothwall user community has a relly good comunity that goes really into the deep of the firewalls. You can download different customized kernels for firewalling purposes and you can do a lot of things.
The user comunity around the sme server is really a very strong one, and I will call it "application and usage oriented" concerned with how a server can be used as a whole, and not only one certain detail like the firewalling. The sme server is also in some ways quite different from many other Linux distributions, because it is designed to do a real job, just from the start. In this way the sme server and the smoothwall has something in common, even though they are quite different products.
It is true that "computer security" does not really has so much to do with the firewall itself. The more dangerous things is related to that trafic firewalls are designed to pass trough, typical related to web server, php, mailservers, shh servers, etc. One thing that make the sme server "safe" as I will see it is that it is quite easy to backup and quite easy to reinstall and restore.
Concerning apples and bananas, it depends much of your apetite, how much computer stuff you want. Are you hungry enough you take them both.
If it is only a question of doeing the job, I'm quite sure the the sme server can do that.
By the way, there is also a wery nice one, floppyfw or floppyfirewall. You can boot it from a CD, a floppy or a USB stick, and its user socity is very strong on Linux kernel firewalling.
http://www.zelow.no/floppyfw/If it was not for all the other firewalls I would certainly use it, and actually I do, but not every day. At the floppyfw user community, one does not discuss such a "far away thing" like a web proxy. You discuss the kernel. It's not aples it's not bananas, it's more loke an exclusive kind of grapes.
The SME server can for sure do the job, but there is a lot of interestings stuff out there.
Arne.